1. Field of the Invention
The invention relates to heat transfer and, more particularly, to a heat sink assembly.
2. Brief Description of Prior Developments
Heat sinks, used for cooling of a device during a test, are known which are loaded against the device under test (DUT). This load is typically provided by a set of springs which compress as the DUT is brought into contact with the heat sink. The resulting load varies around some nominal value with compression varying both in the springs fundamental spring constants and in the distance traveled. The nominal load value is fixed (unless the springs are changed), resulting in widely varying load pressures for varying DUT sizes. The variations in load and in resulting load pressure result in less than optimal load design and, thus, less than optimal thermal performance. This issue is aggravated when the heat sink is a locally compliant type heat sink requiring a particular range of load pressures for best performance. In addition, many typical (although not all) heat sink mounting designs can have unbalanced loads created by the coolant delivery hoses. Some applications now utilize a centrally located dual bellows system for bringing in and returning the coolant. The load in this case can be substantially dependent on coolant flow, with no means for compensating for these variations.